Electrical thermostatic alarm system.



A. GOLDSTBIN. ELECTRICAL THERMOSTATIG -ALARM SYSTEM.

APPLICATION nun MAY 2, 1910.

981,998. Patented Jan.17,1911.

i 9 a re 1 J' 16 6 3 d w 06 w MJWW a ttO i I 01.3 :HUW Z 7 make an cated at different stations.

UNI ED; STATEs PATENT OFFICE.

ALBERT. GOL

permit; OF NEW YORK, N. Y.', ASSIGNOR To INTERNATIONAL LECTRIC PROTECTION CMPANY, A CORPORATION 01 NEW YORK.

' ELECTRICAL THERMosTATIc ALARM SYSTEM.

Specification of-Ltters Patent.

Patented Jan. 17, 1911.

Application iiled May 2, 191a. Serial No.- 558,818.

To all whom it may concern:

Be it known that-,I ALBERT GoLos'r IN,

a citizen of the United States, residing at New York, in the County of New York and State of New York, have'invented a certain new and useful Improvement inElectricztl Thermostatic Alarm Systems, of which the following is a-specification.

The invention relates to an electrical ther- .mostatic alarm system,\ and eonsists, fi rst, 1n the combmatlon whereby two changes must bekproduced in the'cir'cuit, such as a acting upon the alarmvbeforethe said alarm operates: and also in the construction of the thermostat whereby upon the movement of the diaphragm due to expansionof air w1th1n the case, said changes are caused.

Inthis way, a single accidental change occurring on the line, such as a ground or crossing, is prevented from giving a false alarm. j I In the accompanyihg drawing-Figure 1 "is a cross section of my thermostat, and Fig. 2 is an electrical diagram of an alarm circuit including three of said thermostats 10-' .Similar letters and numbers of reference indicate like parts. 3

cup-shaped members 2, 3, between whichthe diaphragm 4 is received and held. Said The circular'case-l comprises two flanged diaphragm is'to be made of'thin sheet metal, preferably the thinnest- "sheet copper procurable, and may be corrugated and r0- vided with a central contact boss 5. member 2 is to be preferably made of steel much heavier. than the member 3, so as'to form the chief support for vt he device. The

member 3 is preferably of a metal that is highly and as thin as will afford the necessary rigidity. Theflange of member 3'has a corrnationti which enters a similar corrugatimi in the flange of member 2. The flange of diaphragm 4 is clamped between said corruj.gated members, so that the diaphragm is thus strained anda close air-tight joint formed between the parts. .The'mcmhcr 3 ma 1 be secured by bending its circumferentia edge 7 over theedge of member 2. I

Centrally disposed in member 2 is' a'block 8 of insulating material, on which are two contact plates 9, 10. In the block is an opena break, by'the thermostat, both.

' the other side of the dia h'ra conductive otheat, such as copper,

ing through which loosely passes av metal rod 11 supported on .a screw 12, which asses through a metal bridge piece 13, whic norturning the milled head 14 so as to'bring' the lower end of rod 11 into desired proximity to the boss .5' on diaphragm 4. The 5 contact plates 9, 10 are respectively connected to terminals'of the circuit wire'a,

1s connected to ter-- while the diaphragm 4 .minals of the circuit wire a. i 1 Air vents 15 (dottedlines Fig. 1) may be made in member 2 and communicate wi thechamber therein on-one side of the diaphragm. In the chamber in member 3 '(ll 16; open at both ends an at its outer and communicating with an opening inthe wall of said chamber; J r

The 0 eration ofthe thermostat is. as fol! lows: The contact piece 11 is first adjusted in suitable proximity to the diaphragmd. When the surrounding atmosphere increases in temperature, the heat is rapidly conducted through the thin metal chamber in member'3 and expands the air thereiln This airv can escape only through the tube 16 'whichis madelong and of small cross sectional area, so as to retard the air .fiow.x The consequence is, that the expansion of the air in the chamber containing the tube is so quick as to be practically an impulse in the confined air body which, be-

ing communicatedto the diaphragm 4, first moves it into contact with rod-11, thus producing a crossing from wire a to wire a,

and t the dia 13 to reak circuit between the terminal plates 9, 10 on wire r1.

In Fig. 2 the thermostat is shown in, an alarm circuit. The wircsa, a are line conn the further upward movement of dnctors connected to opposite poles of the battery A. In the com actor a is a magnet B which controls the two switch levers b and b'. 'In'the conductor a and on opposite sides of the battery A are two magnets C, I). The battery current normally energiZes magnctB, so that a metallic circuit proceeds from one pole of battery A,yby

wire a, to imignet B, to contact point 0, switch lever b, and wire a, through maghragm raises the rod 11 and bridge is a tube until they reach diaphragm continuing t 'tract their armatures per 'ortions. of slots 6, ,f in a more nearly does not receive sufiici ent current to cause it. to actuate 1ts armature. The pivoted armatures E, F of magnets C, D are in bellcrank form. Art the end of each vertical arm ofthe armatures E, F, are formed V- which receive pins G on meet contact points z, y', and so close a local circuit which includes a battery I and electric bell J. In the circuit conductors a, a at N, N, N are interposed as many of the thermostats, shown in, Fig. 1, as there are stations from which it is desired alarms shall be given. The operation is as follows: Assume the diaphragm of the thermostat at N, Fig. 2, to be moved to close contact withits rod. This short-circuits magnet B. The switches b, b then dro .the pointsc and 0*. ircuit is then established through both ma F to bring the upvertlcal position. The pins-G then drop 0 move under the air impulse, bridge 13, thus breaking circuit in wire a at 9 and 10. Magnets-C and ,D thenflfail, and the armatures E, F-return to the position shown .in the drawing. But the pins G on arms H being now, as above stated, at the angles of the slots e, f, readily slide down-the lower portions of said slots, thus permitting the arms H to close at points z' and j the local circuit including the alarm J The alarm then continues sounding .until the air pressure on the diaphragm 4 1s suitably decreased, and until the. parts associated with thearmatures E, F are manu-' ally restored to their original position. It

will be observed, therefore, that this thermostat requires two successive changes in the circuit -to insure its operation; namely, (l) a short-circuiting produced "by the contact of diaphragm 4- and rod' 11, and (2) an opening of the circuit produced by the separation of the bridge piece 13 from the contact plates 9 and 10. The advantages 'of this construction. are- (1) That it ,is impossible for a :single change in thecircnit, such. as an accidental crossing ofthe lines, or a: break, or a ground,

to operate the alarm.

, will then be formed, one including magnet C and thermostats N and'N and the other 'includin magnet D and thermostat N. Hence I? either thermostat N or N be 0 erated, magnet 0 only will respond, Whl e and close circuit at.

nets 0, D, which atthe angles in the slots, Thelifts the contact rod 11 and That a single break in the circuit. wires w1ll not, prevent the alarm from o p-c will respond either magnet then performing the same alarm circuit-closing operation as was previously done by both magnets.

(23) That a single accidental crossing of the 'circuit'wires will not prevent the alarm from operating. Thu's suppose the .a'ccidental crossing to occur at the point Z. Two leads will be formed as before, but in this case, gized, thus performing the first step in lowering the arms H. Now suppose any one of the thermostats'toibe operated, say the thermostat N.

But when the circuit is broken at points 9 and 110, the results are as follows. The breaking at point 10- deenergizes magnet D, which accomplishes the second step in lower"- ing its arm to close the local circuit to the through the alarm, while the magnet D will remain energized, its lead being closed through thermostat N and the accidental circuitreaking contacts 9, 10 at each the!- mostat, one or the other of which comes into operation to deenergize one of the two prewhetherthe crossing is at one side or the other of the working thermostat, will now be apparent.

I claim:

alarm device, controlling means therefor operated 1n two steps by successlve changes in means for producing said changes.

2. In combmation, at electriccircuit, an

- alarm device, controlling meanstherefor operated in two'steps by successive changes. in the electrical condition of said circuit, and thermostatically controlled means for ro; ducing said changes.

trical thermostatcomprising a diaphragm, meanscontrolled by said din completed bv said second change;

51. In, combination, an electric circuit, an

operation.

alarm device and controlling means therefor operated in partby-a closingof saidv both magnets C and D willbe ener The closing of circuit be tween diaphragm 4 and rod ll-does nothing.

alarm. The other magnet 0 remains ener- I in lowering its arm H'to close local circuit-'- the electrical condition of said circuit, and

phra for ,maki-n two changes in the electricah ondi .trollin'g means therefor operated in part by ,if thermostat N- be operated, magnet D only crossin at Z. The necessity for having two '100 viously energized magnets, depending upon 1. In combination, an electric circuit, an

3. The combination in circuit'of an elec-rcircuit and having its operation completed 1 ag by a breaking of said circuit, and thermostatically controlled meansi'or first closing and then" breaking saidcircuit.

3; The combination in circuit; of an electrical thermostatcomprising a case, a diaphragm in said case and operated by air, expansion therein, means controlled by said diaphragmfor first making and then breaking said circuit, and an alarm device operat.

ing only after said break.

6. The combination in circuit of a mag net, a circuit clos ng switch controlled by said 'magnetto move over two successive portions of its path before closing circuit,

terminals'zthe said diaphragm operating, first, to establish a crossing between said line members through saidcontact piece, and second, to open circuit at said terminals.

' '8. The combination of a source of current,

the line members of a circuit, a circuit closer normally energized to close said circuit, two

magnets in one of said line members and disposed on opposite sides of said current source, a local alarm circuit controlled by each of said magnets, fixed terminals in said line member, a loose contact piece bridging said terminals, and a thermostatic diaphragm interposed in the other line; member: the said diaphragm operating, first,'to establish a crossing between, said line members through said contact piece, and second, to opencircuit at said terminals.

In testimony whereof I have afiixed my signature in presence of two Witnesses.

( ALBERT eoLDs'rEIN.

Witnesses: i

GERT'RUDE T. PORTER, 'MA T. MOGARRY. 

